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Larbi Talbi

Bio: Larbi Talbi is an academic researcher from Université du Québec. The author has contributed to research in topics: Microstrip antenna & MIMO. The author has an hindex of 21, co-authored 181 publications receiving 1885 citations. Previous affiliations of Larbi Talbi include Université du Québec en Abitibi-Témiscamingue & Université du Québec en Outaouais.


Papers
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Journal ArticleDOI
TL;DR: In this article, a Fabry-Perot (FP) resonator antenna with a wide gain bandwidth in the X band was proposed, which is attributed to the positive reflection phase gradient of an electromagnetic band gap (EBG) structure, constructed by the combination of two complementary frequency selective surfaces (FSSs).
Abstract: This paper presents a novel design of a Fabry-Perot (FP) resonator antenna with a wide gain bandwidth in X band. The bandwidth enhancement of the antenna is attributed to the positive reflection phase gradient of an electromagnetic band gap (EBG) structure, which is constructed by the combination of two complementary frequency selective surfaces (FSSs). To explain well the design procedure and approach, the EBG structure is modeled as an equivalent circuit and analyzed using the Smith Chart. Experimental results show that the antenna possesses a relative 3 dB gain bandwidth of 28%, from 8.6 GHz to 11.4 GHz, with a peak gain of 13.8 dBi. Moreover, the gain bandwidth can be well covered by the impedance bandwidth for the reflection coefficient ( ${\rm S} _{11}$ ) below $-10~{\rm dB}$ from 8.6 GHz to 11.2 GHz.

182 citations

Journal ArticleDOI
TL;DR: In this article, a 4 times 4 two-layer Butler matrix based on a broadband broadband 2-layer slot-coupled directional coupler is presented and implemented at 58 GHz using coplanar waveguide technology.
Abstract: In this paper, a novel 4 times 4 two-layer Butler matrix based on a broad-band two-layer slot-coupled directional coupler is presented and implemented at 58 GHz using coplanar waveguide technology With the slot-coupled directional coupler, the proposed matrix was designed without using any crossovers as used in conventional Butler matrices, which leads to significant size reduction and loss minimization To examine the performance of the proposed matrix, experimental prototypes of the multilayer directional coupler and the Butler matrix were fabricated and measured Furthermore, a four-antenna array was also designed and fabricated at 58 GHz and then connected to the matrix to form a beamforming antenna system As a result, four orthogonal beams at -45deg, -15deg, 15deg, and 45deg are produced Measured results on the entire system agree well with the theoretical predictions, validating the proposed design

133 citations

Journal ArticleDOI
TL;DR: In this article, the presence of the human body may be approximated by a conducting circular cylinder at microwave frequencies, and a perfect tool such as the uniform theory of diffraction may be used to predict the diffracted field over a smooth circular surface.
Abstract: We demonstrate that in indoor radio propagation modeling, the presence of the human body may be approximated by a conducting circular cylinder at microwave frequencies. Therefore, a perfect tool such as the uniform theory of diffraction may be used to predict the diffracted field over a smooth circular surface. To validate the model, vertically and horizontally polarized continuous wave (CW) measurements were performed at 10.5 GHz between two fixed terminals inside a room along with the presence of an obstacle (person or metallic cylinder) moving along predetermined parallel and perpendicularly crossing paths with respect to the line-of-sight direction. Results indicate that there is a strong correlation between the effects of the human body and those of a conducting circular cylinder. The simulation results successfully agree with the CW experimental measurements.

121 citations

Journal ArticleDOI
Abstract: In this paper, a cylindrical electromagnetic bandgap (CEBG) structure composed of infinite metallic wires is analyzed, designed and used as a model to develop a new reconfigurable directive antenna. This structure is circularly and radially periodic, and it is excited at its center using an omnidirectional source. The analysis is based on calculating the transmission and reflection coefficients of a single cylindrical frequency selective surface (FSS) and then, considering only the fundamental mode interaction, deducing the frequency response of the CEBG structure composed of multiple cylindrical FSSs. For this structure, new analytical formulas are derived, and their accuracy is assessed compared to those obtained by the finite-difference time-domain method. As in rectangularly periodic structure case, the frequency response of the CEBG structure exhibits pass-bands and bandgaps, and it is possible to obtain directive beams by introducing defects in the periodic structure. Using this concept, a new antenna was developed to obtain a controllable directive beam. An antenna prototype, without control, was designed, fabricated, and tested. An excellent agreement was obtained between theory and experiment for both return loss and radiation patterns.

99 citations

Proceedings ArticleDOI
03 Jul 2005
TL;DR: In this article, a new configuration of a coplanar waveguide (CPW) beamforming 8-port Butler matrix operating at 5.8 GHz is presented, which is based on a novel CPW multilayer directional coupler.
Abstract: In this paper, a new configuration of a coplanar waveguide (CPW) beamforming 8-port Butler matrix operating at 5.8 GHz is presented. This matrix is based on a novel CPW multilayer directional coupler. The main objective of the proposed coupler is to avoid using crossovers as employed in conventional Butler matrices. To examine the performance of the proposed matrix, an experimental prototype was fabricated and measured, and the obtained results confirm the proposed approach.

96 citations


Cited by
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Journal ArticleDOI
TL;DR: An overview of emerging technologies and system research that might lead to ubiquitous THz communication systems in the future is given.
Abstract: The increasing demand of unoccupied and unregulated bandwidth for wireless communication systems will inevitably lead to the extension of operation frequencies toward the lower THz frequency range. Higher carrier frequencies will allow for fast transmission of huge amounts of data as needed for new emerging applications. Despite the tremendous hurdles that have to be overcome with regard to sources and detectors, circuit and antenna technology and system architecture to realize ultrafast data transmission in a scenario with extensive transmission loss, a new area of research is beginning to form. In this article we give an overview of emerging technologies and system research that might lead to ubiquitous THz communication systems in the future.

878 citations

Journal ArticleDOI
TL;DR: This paper provides an overview of the existing multibeam antenna technologies which include the passiveMultibeam antennas (MBAs) based on quasi-optical components and beamforming circuits, multibeams phased-array antennas enabled by various phase-shifting methods, and digital MBAs with different system architectures.
Abstract: With the demanding system requirements for the fifth-generation (5G) wireless communications and the severe spectrum shortage at conventional cellular frequencies, multibeam antenna systems operating in the millimeter-wave frequency bands have attracted a lot of research interest and have been actively investigated. They represent the key antenna technology for supporting a high data transmission rate, an improved signal-to-interference-plus-noise ratio, an increased spectral and energy efficiency, and versatile beam shaping, thereby holding a great promise in serving as the critical infrastructure for enabling beamforming and massive multiple-input multiple-output (MIMO) that boost the 5G. This paper provides an overview of the existing multibeam antenna technologies which include the passive multibeam antennas (MBAs) based on quasi-optical components and beamforming circuits, multibeam phased-array antennas enabled by various phase-shifting methods, and digital MBAs with different system architectures. Specifically, their principles of operation, design, and implementation, as well as a number of illustrative application examples are reviewed. Finally, the suitability of these MBAs for the future 5G massive MIMO wireless systems as well as the associated challenges is discussed.

737 citations

Book
24 Nov 2008
TL;DR: In this paper, the FDTD method for periodic structure analysis is used for periodic structures analysis of EBG surfaces and low profile wire antennas are used for EBG surface wave antennas.
Abstract: Preface 1. Introduction 2. FDTD Method for periodic structure analysis 3. EBG Characterizations and classifications 4. Design and optimizations of EBG structures 5. Patch antennas with EBG structures 6. Low profile wire antennas on EBG surfaces 7. Surface wave antennas Appendix: EBG literature review.

634 citations

Journal ArticleDOI
TL;DR: A survey of the mmWave propagation characteristics, channel modeling, and design guidelines, such as system and antenna design considerations for mmWave, including the link budget of the network, which are essential for mm Wave communication systems design is presented.
Abstract: The millimeter wave (mmWave) frequency band spanning from 30 to 300 GHz constitutes a substantial portion of the unused frequency spectrum, which is an important resource for future wireless communication systems in order to fulfill the escalating capacity demand. Given the improvements in integrated components and enhanced power efficiency at high frequencies, wireless systems can operate in the mmWave frequency band. In this paper, we present a survey of the mmWave propagation characteristics, channel modeling, and design guidelines, such as system and antenna design considerations for mmWave, including the link budget of the network, which are essential for mmWave communication systems. We commence by introducing the main channel propagation characteristics of mmWaves followed by channel modeling and design guidelines. Then, we report on the main measurement and modeling campaigns conducted in order to understand the mmWave band’s properties and present the associated channel models. We survey the different channel models focusing on the channel models available for the 28, 38, 60, and 73 GHz frequency bands. Finally, we present the mmWave channel model and its challenges in the context of mmWave communication systems design.

512 citations